An experimental design for the control and assembly of magnetic microwheels
An experimental design for the control and assembly of magnetic microwheels
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DOI：
10.1063/5.0010805
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发表时间：
2020-09-01
影响因子：
1.6
通讯作者：
Neeves, K. B.
中科院分区：
文献类型：
--
作者：
Roth, E. J.;Zimmermann, C. J.;Neeves, K. B.
超顺磁性胶体粒子可以可逆地组装成被称为微轮（mu wheels）的轮状结构，微轮由于摩擦在表面上滚动，并且可以使用旋转磁场以用户控制的速度和方向驱动。在这里，我们描述了硬件和软件来创建和控制磁场，组装和指导车轮运动和光学可视化它们。出于便携性、适应性和低成本的考虑，我们构建了一个挤压铝散热框架，该框架结合了开放式光学器件和配有高磁导率芯的音频扬声器线圈。开发了开源软件来定义磁场的大小，频率和方向，允许通过二维（2D）和三维（3D）流体环境实时控制mu轮的操纵杆。通过这种硬件和软件的结合，mu轮通过使用0.75 mT-2.5 mT磁场，旋转频率为5 Hz-40 Hz，样本量可达5 × 5 × 5 cm(3)，以高达50 μ m/s的速度转换。铝卷夹的散热使样品温度保持在环境温度的3摄氏度以内，这一范围有利于生物应用。通过这种设计，mu轮可以在微米到厘米的长度范围内以二维和三维网络进行操作和成像。
Superparamagnetic colloidal particles can be reversibly assembled into wheel-like structures called microwheels (mu wheels), which roll on surfaces due to friction and can be driven at user-controlled speeds and directions using rotating magnetic fields. Here, we describe the hardware and software to create and control the magnetic fields that assemble and direct mu wheel motion and the optics to visualize them. Motivated by portability, adaptability, and low-cost, an extruded aluminum heat-dissipating frame incorporating open optics and audio speaker coils outfitted with high magnetic permeability cores was constructed. Open-source software was developed to define the magnitude, frequency, and orientation of the magnetic field, allowing for real-time joystick control of mu wheels through two-dimensional (2D) and three-dimensional (3D) fluidic environments. With this combination of hardware and software, mu wheels translate at speeds up to 50 mu m/s through sample sizes up to 5 x 5 x 5 cm(3) using 0.75 mT-2.5 mT magnetic fields with rotation frequencies of 5 Hz-40 Hz. Heat dissipation by aluminum coil clamps maintained sample temperatures within 3 degrees C of ambient temperature, a range conducive for biological applications. With this design, mu wheels can be manipulated and imaged in 2D and 3D networks at length scales of micrometers to centimeters.